2 * Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
3 * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation version 2 of the License.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
32 #include <sys/select.h>
34 #include <sys/types.h>
35 #include <sys/socket.h>
38 #include <sys/ioctl.h>
39 #include <linux/types.h>
40 #include <linux/netlink.h>
43 #include "udev_rules.h"
45 #include "udev_selinux.h"
47 static struct udev_rules rules;
48 static int udevd_sock = -1;
49 static int uevent_netlink_sock = -1;
50 static int inotify_fd = -1;
53 static int signal_pipe[2] = {-1, -1};
54 static volatile int sigchilds_waiting;
55 static volatile int udev_exit;
56 static volatile int reload_config;
57 static int run_exec_q;
58 static int stop_exec_q;
59 static int max_childs;
60 static int max_childs_running;
61 static char udev_log[32];
63 static LIST_HEAD(exec_list);
64 static LIST_HEAD(running_list);
68 void log_message(int priority, const char *format, ...)
72 if (priority > udev_log_priority)
75 va_start(args, format);
76 vsyslog(priority, format, args);
81 static void asmlinkage udev_event_sig_handler(int signum)
83 if (signum == SIGALRM)
87 static int udev_event_process(struct udevd_uevent_msg *msg)
94 /* set signal handlers */
95 memset(&act, 0x00, sizeof(act));
96 act.sa_handler = (void (*)(int)) udev_event_sig_handler;
97 sigemptyset (&act.sa_mask);
99 sigaction(SIGALRM, &act, NULL);
101 /* reset to default */
102 act.sa_handler = SIG_DFL;
103 sigaction(SIGINT, &act, NULL);
104 sigaction(SIGTERM, &act, NULL);
105 sigaction(SIGCHLD, &act, NULL);
106 sigaction(SIGHUP, &act, NULL);
108 /* trigger timeout to prevent hanging processes */
109 alarm(UDEV_ALARM_TIMEOUT);
111 /* reconstruct event environment from message */
112 for (i = 0; msg->envp[i]; i++)
113 putenv(msg->envp[i]);
115 udev = udev_device_init();
118 strlcpy(udev->action, msg->action, sizeof(udev->action));
119 sysfs_device_set_values(udev->dev, msg->devpath, msg->subsystem, msg->driver);
120 udev->devt = msg->devt;
122 retval = udev_device_event(&rules, udev);
124 /* run programs collected by RUN-key*/
125 if (retval == 0 && !udev->ignore_device && udev_run) {
126 struct name_entry *name_loop;
128 dbg("executing run list");
129 list_for_each_entry(name_loop, &udev->run_list, node) {
130 if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
131 pass_env_to_socket(&name_loop->name[strlen("socket:")], udev->dev->devpath, udev->action);
133 char program[PATH_SIZE];
135 strlcpy(program, name_loop->name, sizeof(program));
136 udev_rules_apply_format(udev, program, sizeof(program));
137 if (run_program(program, udev->dev->subsystem, NULL, 0, NULL,
138 (udev_log_priority >= LOG_INFO)))
144 udev_device_cleanup(udev);
154 static void export_event_state(struct udevd_uevent_msg *msg, enum event_state state)
156 char filename[PATH_SIZE];
157 char filename_failed[PATH_SIZE];
158 char target[PATH_SIZE];
159 size_t start, end, i;
160 struct udevd_uevent_msg *loop_msg;
162 /* add location of queue files */
163 strlcpy(filename, udev_root, sizeof(filename));
164 strlcat(filename, "/", sizeof(filename));
165 start = strlcat(filename, EVENT_QUEUE_DIR, sizeof(filename));
166 end = strlcat(filename, msg->devpath, sizeof(filename));
167 if (end > sizeof(filename))
168 end = sizeof(filename);
170 /* replace '/' to transform path into a filename */
171 for (i = start+1; i < end; i++)
172 if (filename[i] == '/')
173 filename[i] = PATH_TO_NAME_CHAR;
175 /* add location of failed files */
176 strlcpy(filename_failed, udev_root, sizeof(filename_failed));
177 strlcat(filename_failed, "/", sizeof(filename_failed));
178 start = strlcat(filename_failed, EVENT_FAILED_DIR, sizeof(filename_failed));
179 end = strlcat(filename_failed, msg->devpath, sizeof(filename_failed));
180 if (end > sizeof(filename_failed))
181 end = sizeof(filename_failed);
183 /* replace '/' to transform path into a filename */
184 for (i = start+1; i < end; i++)
185 if (filename_failed[i] == '/')
186 filename_failed[i] = PATH_TO_NAME_CHAR;
190 unlink(filename_failed);
191 delete_path(filename_failed);
193 strlcpy(target, sysfs_path, sizeof(target));
194 strlcat(target, msg->devpath, sizeof(target));
195 create_path(filename);
196 symlink(target, filename);
200 unlink(filename_failed);
201 delete_path(filename_failed);
203 /* don't remove, if events for the same path are still pending */
204 list_for_each_entry(loop_msg, &running_list, node)
205 if (loop_msg->devpath && strcmp(loop_msg->devpath, msg->devpath) == 0)
208 list_for_each_entry(loop_msg, &exec_list, node)
209 if (loop_msg->devpath && strcmp(loop_msg->devpath, msg->devpath) == 0)
212 /* move failed events to the failed directory */
213 if (state == EVENT_FAILED) {
214 create_path(filename_failed);
215 rename(filename, filename_failed);
220 /* clean up the queue directory */
221 delete_path(filename);
227 static void msg_queue_delete(struct udevd_uevent_msg *msg)
229 list_del(&msg->node);
231 /* mark as failed, if add event returns non-zero */
232 if (msg->exitstatus && strcmp(msg->action, "add") == 0)
233 export_event_state(msg, EVENT_FAILED);
235 export_event_state(msg, EVENT_FINISHED);
240 static void udev_event_run(struct udevd_uevent_msg *msg)
249 close(uevent_netlink_sock);
253 close(signal_pipe[READ_END]);
254 close(signal_pipe[WRITE_END]);
257 logging_init("udevd-event");
258 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
260 retval = udev_event_process(msg);
261 info("seq %llu finished", msg->seqnum);
268 err("fork of child failed: %s", strerror(errno));
269 msg_queue_delete(msg);
272 /* get SIGCHLD in main loop */
273 info("seq %llu forked, pid [%d], '%s' '%s', %ld seconds old",
274 msg->seqnum, pid, msg->action, msg->subsystem, time(NULL) - msg->queue_time);
279 static void msg_queue_insert(struct udevd_uevent_msg *msg)
281 char filename[PATH_SIZE];
284 msg->queue_time = time(NULL);
286 strlcpy(filename, udev_root, sizeof(filename));
287 strlcat(filename, "/" EVENT_SEQNUM, sizeof(filename));
288 fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
293 len = sprintf(str, "%llu\n", msg->seqnum);
298 export_event_state(msg, EVENT_QUEUED);
300 /* run all events with a timeout set immediately */
301 if (msg->timeout != 0) {
302 list_add_tail(&msg->node, &running_list);
307 list_add_tail(&msg->node, &exec_list);
311 static int mem_size_mb(void)
319 f = open("/proc/meminfo", O_RDONLY);
323 len = read(f, buf, sizeof(buf)-1);
330 pos = strstr(buf, "MemTotal: ");
334 if (sscanf(pos, "MemTotal: %ld kB", &memsize) != 1)
337 return memsize / 1024;
340 static int cpu_count(void)
348 f = open("/proc/stat", O_RDONLY);
352 len = read(f, buf, sizeof(buf)-1);
358 pos = strstr(buf, "cpu");
362 while (pos != NULL) {
363 if (strncmp(pos, "cpu", 3) == 0 &&isdigit(pos[3]))
365 pos = strstr(&pos[3], "cpu");
373 static int running_processes(void)
381 f = open("/proc/stat", O_RDONLY);
385 len = read(f, buf, sizeof(buf)-1);
391 pos = strstr(buf, "procs_running ");
395 if (sscanf(pos, "procs_running %u", &running) != 1)
401 /* return the number of process es in our session, count only until limit */
402 static int running_processes_in_session(pid_t session, int limit)
408 dir = opendir("/proc");
412 /* read process info from /proc */
413 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
419 pid_t ppid, pgrp, sess;
422 if (!isdigit(dent->d_name[0]))
425 snprintf(procdir, sizeof(procdir), "/proc/%s/stat", dent->d_name);
426 procdir[sizeof(procdir)-1] = '\0';
428 f = open(procdir, O_RDONLY);
432 len = read(f, line, sizeof(line)-1);
440 /* skip ugly program name */
441 pos = strrchr(line, ')') + 2;
445 if (sscanf(pos, "%c %d %d %d ", &state, &ppid, &pgrp, &sess) != 4)
448 /* count only processes in our session */
452 /* count only running, no sleeping processes */
457 if (limit > 0 && running >= limit)
465 static int compare_devpath(const char *running, const char *waiting)
469 for (i = 0; i < PATH_SIZE; i++) {
470 /* identical device event found */
471 if (running[i] == '\0' && waiting[i] == '\0')
474 /* parent device event found */
475 if (running[i] == '\0' && waiting[i] == '/')
478 /* child device event found */
479 if (running[i] == '/' && waiting[i] == '\0')
482 /* no matching event */
483 if (running[i] != waiting[i])
490 /* returns still running task for the same device, its parent or its physical device */
491 static int running_with_devpath(struct udevd_uevent_msg *msg, int limit)
493 struct udevd_uevent_msg *loop_msg;
494 int childs_count = 0;
496 list_for_each_entry(loop_msg, &running_list, node) {
497 if (limit && childs_count++ > limit) {
498 dbg("%llu, maximum number (%i) of child reached", msg->seqnum, childs_count);
502 /* return running parent/child device event */
503 if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
504 dbg("%llu, child device event still running %llu (%s)",
505 msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
509 /* return running physical device event */
510 if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
511 if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
512 dbg("%llu, physical device event still running %llu (%s)",
513 msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
521 /* exec queue management routine executes the events and serializes events in the same sequence */
522 static void msg_queue_manager(void)
524 struct udevd_uevent_msg *loop_msg;
525 struct udevd_uevent_msg *tmp_msg;
528 if (list_empty(&exec_list))
531 running = running_processes();
532 dbg("%d processes runnning on system", running);
534 running = max_childs_running;
536 list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) {
537 /* check running processes in our session and possibly throttle */
538 if (running >= max_childs_running) {
539 running = running_processes_in_session(sid, max_childs_running+10);
540 dbg("at least %d processes running in session", running);
541 if (running >= max_childs_running) {
542 dbg("delay seq %llu, too many processes already running", loop_msg->seqnum);
547 /* don't run two processes for the same devpath and wait for the parent*/
548 if (running_with_devpath(loop_msg, max_childs)) {
549 dbg("delay seq %llu (%s)", loop_msg->seqnum, loop_msg->devpath);
553 /* move event to run list */
554 list_move_tail(&loop_msg->node, &running_list);
555 udev_event_run(loop_msg);
557 dbg("moved seq %llu to running list", loop_msg->seqnum);
561 static struct udevd_uevent_msg *get_msg_from_envbuf(const char *buf, int buf_size)
565 struct udevd_uevent_msg *msg;
566 char *physdevdriver_key = NULL;
570 msg = malloc(sizeof(struct udevd_uevent_msg) + buf_size);
573 memset(msg, 0x00, sizeof(struct udevd_uevent_msg) + buf_size);
575 /* copy environment buffer and reconstruct envp */
576 memcpy(msg->envbuf, buf, buf_size);
578 for (i = 0; (bufpos < buf_size) && (i < UEVENT_NUM_ENVP-2); i++) {
582 key = &msg->envbuf[bufpos];
583 keylen = strlen(key);
585 bufpos += keylen + 1;
586 dbg("add '%s' to msg.envp[%i]", msg->envp[i], i);
588 /* remember some keys for further processing */
589 if (strncmp(key, "ACTION=", 7) == 0)
590 msg->action = &key[7];
591 else if (strncmp(key, "DEVPATH=", 8) == 0)
592 msg->devpath = &key[8];
593 else if (strncmp(key, "SUBSYSTEM=", 10) == 0)
594 msg->subsystem = &key[10];
595 else if (strncmp(key, "DRIVER=", 7) == 0)
596 msg->driver = &key[7];
597 else if (strncmp(key, "SEQNUM=", 7) == 0)
598 msg->seqnum = strtoull(&key[7], NULL, 10);
599 else if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
600 msg->physdevpath = &key[12];
601 else if (strncmp(key, "PHYSDEVDRIVER=", 14) == 0)
602 physdevdriver_key = key;
603 else if (strncmp(key, "MAJOR=", 6) == 0)
604 maj = strtoull(&key[6], NULL, 10);
605 else if (strncmp(key, "MINOR=", 6) == 0)
606 min = strtoull(&key[6], NULL, 10);
607 else if (strncmp(key, "TIMEOUT=", 8) == 0)
608 msg->timeout = strtoull(&key[8], NULL, 10);
610 msg->devt = makedev(maj, min);
611 msg->envp[i++] = "UDEVD_EVENT=1";
613 if (msg->driver == NULL && msg->physdevpath == NULL && physdevdriver_key != NULL) {
614 /* for older kernels DRIVER is empty for a bus device, export PHYSDEVDRIVER as DRIVER */
615 msg->envp[i++] = &physdevdriver_key[7];
616 msg->driver = &physdevdriver_key[14];
621 if (msg->devpath == NULL || msg->action == NULL) {
622 info("DEVPATH or ACTION missing, ignore message");
629 /* receive the udevd message from userspace */
630 static void get_ctrl_msg(void)
632 struct udevd_ctrl_msg ctrl_msg;
635 struct cmsghdr *cmsg;
638 char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
641 memset(&ctrl_msg, 0x00, sizeof(struct udevd_ctrl_msg));
642 iov.iov_base = &ctrl_msg;
643 iov.iov_len = sizeof(struct udevd_ctrl_msg);
645 memset(&smsg, 0x00, sizeof(struct msghdr));
648 smsg.msg_control = cred_msg;
649 smsg.msg_controllen = sizeof(cred_msg);
651 size = recvmsg(udevd_sock, &smsg, 0);
654 err("unable to receive user udevd message: %s", strerror(errno));
657 cmsg = CMSG_FIRSTHDR(&smsg);
658 cred = (struct ucred *) CMSG_DATA(cmsg);
660 if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
661 err("no sender credentials received, message ignored");
665 if (cred->uid != 0) {
666 err("sender uid=%i, message ignored", cred->uid);
670 if (strncmp(ctrl_msg.magic, UDEVD_CTRL_MAGIC, sizeof(UDEVD_CTRL_MAGIC)) != 0 ) {
671 err("message magic '%s' doesn't match, ignore it", ctrl_msg.magic);
675 switch (ctrl_msg.type) {
676 case UDEVD_CTRL_STOP_EXEC_QUEUE:
677 info("udevd message (STOP_EXEC_QUEUE) received");
680 case UDEVD_CTRL_START_EXEC_QUEUE:
681 info("udevd message (START_EXEC_QUEUE) received");
685 case UDEVD_CTRL_SET_LOG_LEVEL:
686 intval = (int *) ctrl_msg.buf;
687 info("udevd message (SET_LOG_PRIORITY) received, udev_log_priority=%i", *intval);
688 udev_log_priority = *intval;
689 sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
692 case UDEVD_CTRL_SET_MAX_CHILDS:
693 intval = (int *) ctrl_msg.buf;
694 info("udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i", *intval);
695 max_childs = *intval;
697 case UDEVD_CTRL_SET_MAX_CHILDS_RUNNING:
698 intval = (int *) ctrl_msg.buf;
699 info("udevd message (UDEVD_SET_MAX_CHILDS_RUNNING) received, max_childs=%i", *intval);
700 max_childs_running = *intval;
702 case UDEVD_CTRL_RELOAD_RULES:
703 info("udevd message (RELOAD_RULES) received");
707 err("unknown control message type");
711 /* receive the kernel user event message and do some sanity checks */
712 static struct udevd_uevent_msg *get_netlink_msg(void)
714 struct udevd_uevent_msg *msg;
717 static char buffer[UEVENT_BUFFER_SIZE+512];
720 size = recv(uevent_netlink_sock, &buffer, sizeof(buffer), 0);
723 err("unable to receive kernel netlink message: %s", strerror(errno));
727 if ((size_t)size > sizeof(buffer)-1)
728 size = sizeof(buffer)-1;
730 dbg("uevent_size=%zi", size);
732 /* start of event payload */
733 bufpos = strlen(buffer)+1;
734 msg = get_msg_from_envbuf(&buffer[bufpos], size-bufpos);
738 /* validate message */
739 pos = strchr(buffer, '@');
741 err("invalid uevent '%s'", buffer);
747 if (msg->action == NULL) {
748 info("no ACTION in payload found, skip event '%s'", buffer);
753 if (strcmp(msg->action, buffer) != 0) {
754 err("ACTION in payload does not match uevent, skip event '%s'", buffer);
762 static void asmlinkage sig_handler(int signum)
770 /* set flag, then write to pipe if needed */
771 sigchilds_waiting = 1;
778 /* write to pipe, which will wakeup select() in our mainloop */
779 write(signal_pipe[WRITE_END], "", 1);
782 static void udev_done(int pid, int exitstatus)
784 /* find msg associated with pid and delete it */
785 struct udevd_uevent_msg *msg;
787 list_for_each_entry(msg, &running_list, node) {
788 if (msg->pid == pid) {
789 info("seq %llu, pid [%d] exit with %i, %ld seconds old", msg->seqnum, msg->pid,
790 exitstatus, time(NULL) - msg->queue_time);
791 msg->exitstatus = exitstatus;
792 msg_queue_delete(msg);
794 /* there may be events waiting with the same devpath */
801 static void reap_sigchilds(void)
807 pid = waitpid(-1, &status, WNOHANG);
810 if (WIFEXITED(status))
811 status = WEXITSTATUS(status);
812 else if (WIFSIGNALED(status))
813 status = WTERMSIG(status) + 128;
816 udev_done(pid, status);
820 static int init_udevd_socket(void)
822 struct sockaddr_un saddr;
824 const int feature_on = 1;
827 memset(&saddr, 0x00, sizeof(saddr));
828 saddr.sun_family = AF_LOCAL;
829 /* use abstract namespace for socket path */
830 strcpy(&saddr.sun_path[1], UDEVD_CTRL_SOCK_PATH);
831 addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
833 udevd_sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
834 if (udevd_sock == -1) {
835 err("error getting socket: %s", strerror(errno));
839 /* the bind takes care of ensuring only one copy running */
840 retval = bind(udevd_sock, (struct sockaddr *) &saddr, addrlen);
842 err("bind failed: %s", strerror(errno));
848 /* enable receiving of the sender credentials */
849 setsockopt(udevd_sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
854 static int init_uevent_netlink_sock(void)
856 struct sockaddr_nl snl;
857 const int buffersize = 16 * 1024 * 1024;
860 memset(&snl, 0x00, sizeof(struct sockaddr_nl));
861 snl.nl_family = AF_NETLINK;
862 snl.nl_pid = getpid();
865 uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
866 if (uevent_netlink_sock == -1) {
867 err("error getting socket: %s", strerror(errno));
871 /* set receive buffersize */
872 setsockopt(uevent_netlink_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
874 retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl, sizeof(struct sockaddr_nl));
876 err("bind failed: %s", strerror(errno));
877 close(uevent_netlink_sock);
878 uevent_netlink_sock = -1;
884 static void export_initial_seqnum(void)
886 char filename[PATH_SIZE];
891 strlcpy(filename, sysfs_path, sizeof(filename));
892 strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
893 fd = open(filename, O_RDONLY);
895 len = read(fd, seqnum, sizeof(seqnum)-1);
899 strcpy(seqnum, "0\n");
902 strlcpy(filename, udev_root, sizeof(filename));
903 strlcat(filename, "/" EVENT_SEQNUM, sizeof(filename));
904 create_path(filename);
905 fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
907 write(fd, seqnum, len);
912 int main(int argc, char *argv[], char *envp[])
916 struct sigaction act;
924 logging_init("udevd");
927 dbg("version %s", UDEV_VERSION);
929 /* parse commandline options */
930 for (i = 1 ; i < argc; i++) {
932 if (strcmp(arg, "--daemon") == 0 || strcmp(arg, "-d") == 0)
934 else if (strcmp(arg, "--help") == 0 || strcmp(arg, "-h") == 0) {
935 printf("Usage: udevd [--help] [--daemon]\n");
938 fprintf(stderr, "unrecognized option '%s'\n", arg);
939 err("unrecognized option '%s'\n", arg);
944 fprintf(stderr, "root privileges required\n");
945 err("root privileges required");
949 /* init sockets to receive events */
950 if (init_udevd_socket() < 0) {
951 if (errno == EADDRINUSE) {
952 fprintf(stderr, "another udev daemon already running\n");
953 err("another udev daemon already running");
956 fprintf(stderr, "error initializing udevd socket\n");
957 err("error initializing udevd socket");
963 if (init_uevent_netlink_sock() < 0) {
964 fprintf(stderr, "error initializing netlink socket\n");
965 err("error initializing netlink socket");
970 /* parse the rules and keep them in memory */
972 udev_rules_init(&rules, 1);
974 export_initial_seqnum();
982 dbg("daemonized fork running");
985 err("fork of daemon failed: %s", strerror(errno));
989 dbg("child [%u] running, parent exits", pid);
995 /* redirect std fd's */
996 fd = open("/dev/null", O_RDWR);
998 dup2(fd, STDIN_FILENO);
999 dup2(fd, STDOUT_FILENO);
1000 dup2(fd, STDERR_FILENO);
1001 if (fd > STDERR_FILENO)
1004 err("error opening /dev/null: %s", strerror(errno));
1006 /* set scheduling priority for the daemon */
1007 setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
1012 /* become session leader */
1014 dbg("our session is %d", sid);
1016 /* OOM_DISABLE == -17 */
1017 fd = open("/proc/self/oom_adj", O_RDWR);
1019 err("error disabling OOM: %s", strerror(errno));
1021 write(fd, "-17", 3);
1025 /* setup signal handler pipe */
1026 retval = pipe(signal_pipe);
1028 err("error getting pipes: %s", strerror(errno));
1032 retval = fcntl(signal_pipe[READ_END], F_GETFL, 0);
1034 err("error fcntl on read pipe: %s", strerror(errno));
1037 retval = fcntl(signal_pipe[READ_END], F_SETFL, retval | O_NONBLOCK);
1039 err("error fcntl on read pipe: %s", strerror(errno));
1043 retval = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
1045 err("error fcntl on write pipe: %s", strerror(errno));
1048 retval = fcntl(signal_pipe[WRITE_END], F_SETFL, retval | O_NONBLOCK);
1050 err("error fcntl on write pipe: %s", strerror(errno));
1054 /* set signal handlers */
1055 memset(&act, 0x00, sizeof(struct sigaction));
1056 act.sa_handler = (void (*)(int)) sig_handler;
1057 sigemptyset(&act.sa_mask);
1058 act.sa_flags = SA_RESTART;
1059 sigaction(SIGINT, &act, NULL);
1060 sigaction(SIGTERM, &act, NULL);
1061 sigaction(SIGCHLD, &act, NULL);
1062 sigaction(SIGHUP, &act, NULL);
1064 /* watch rules directory */
1065 inotify_fd = inotify_init();
1066 if (inotify_fd >= 0)
1067 inotify_add_watch(inotify_fd, udev_rules_filename, IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1068 else if (errno == ENOSYS)
1069 err("the kernel does not support inotify, udevd can't monitor configuration file changes");
1071 err("inotify_init failed: %s", strerror(errno));
1073 /* maximum limit of forked childs */
1074 value = getenv("UDEVD_MAX_CHILDS");
1076 max_childs = strtoul(value, NULL, 10);
1078 int memsize = mem_size_mb();
1080 max_childs = 128 + (memsize / 4);
1082 max_childs = UDEVD_MAX_CHILDS;
1084 info("initialize max_childs to %u", max_childs);
1086 /* start to throttle forking if maximum number of _running_ childs is reached */
1087 value = getenv("UDEVD_MAX_CHILDS_RUNNING");
1089 max_childs_running = strtoull(value, NULL, 10);
1091 int cpus = cpu_count();
1093 max_childs_running = 8 + (8 * cpus);
1095 max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
1097 info("initialize max_childs_running to %u", max_childs_running);
1099 /* clear environment for forked event processes */
1102 /* export log_priority , as called programs may want to follow that setting */
1103 sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
1107 maxfd = UDEV_MAX(maxfd, uevent_netlink_sock);
1108 maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
1109 maxfd = UDEV_MAX(maxfd, inotify_fd);
1111 while (!udev_exit) {
1112 struct udevd_uevent_msg *msg;
1116 FD_SET(signal_pipe[READ_END], &readfds);
1117 FD_SET(udevd_sock, &readfds);
1118 FD_SET(uevent_netlink_sock, &readfds);
1119 if (inotify_fd >= 0)
1120 FD_SET(inotify_fd, &readfds);
1122 fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
1125 err("error in select: %s", strerror(errno));
1129 /* get control message */
1130 if (FD_ISSET(udevd_sock, &readfds))
1133 /* get netlink message */
1134 if (FD_ISSET(uevent_netlink_sock, &readfds)) {
1135 msg = get_netlink_msg();
1137 msg_queue_insert(msg);
1140 /* received a signal, clear our notification pipe */
1141 if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
1144 read(signal_pipe[READ_END], &buf, sizeof(buf));
1147 /* rules directory inotify watch */
1148 if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
1151 /* discard all possible events, we can just reload the config */
1152 if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes) {
1156 buf = malloc(nbytes);
1158 err("error getting buffer for inotify, disable watching");
1162 read(inotify_fd, buf, nbytes);
1167 /* rules changed, set by inotify or a HUP signal */
1168 if (reload_config) {
1170 udev_rules_cleanup(&rules);
1171 udev_rules_init(&rules, 1);
1174 /* forked child has returned */
1175 if (sigchilds_waiting) {
1176 sigchilds_waiting = 0;
1183 msg_queue_manager();
1189 udev_rules_cleanup(&rules);
1192 if (signal_pipe[READ_END] >= 0)
1193 close(signal_pipe[READ_END]);
1194 if (signal_pipe[WRITE_END] >= 0)
1195 close(signal_pipe[WRITE_END]);
1197 if (udevd_sock >= 0)
1199 if (inotify_fd >= 0)
1201 if (uevent_netlink_sock >= 0)
1202 close(uevent_netlink_sock);